Vibilia stebbingi Behning & Woltereck 1912

Vibilia stebbingi Behning & Woltereck (Figs 24 & 25)

Vibilia stebbingi Behning & Woltereck, 1912: 5–6, figs 1­3. — Behning 1913a: 529, 533. Behning 1913b: 217–218. Stephensen 1918: 40–41, fig. 12. Behning 1925: 482–484, figs 13–22. Behning 1927: 118, 121 (Table). Pirlot 1929: 96–97. Barnard 1930: 403­404. Chevreux 1935: 175. Hurley 1960b: 279. Grice & Hart 1962: 300. Kane 1962: 298–299. Hurley 1969: 33, pl. 18 (map­part). Dick 1970: 34 (key), 53. Semenova 1973: 172. Semenova 1976: 138, 139 (Table). Thurston 1976: 404–405. Madin & Harbison 1977. 453 (Table 2), 454. Shulenberger 1977: 378 (Table). Tranter 1977: 647, 648 (Table). Brusca 1981: 18 (key), 39. Vinogradov et al. 1982: 206–208, fig. 103. Barkhatov & Vinogradov 1988: 168 (Table), 172, 176. Vinogradov 1990a: 55, 93 (Table). Zeidler 1992: 96. De Broyer & Jazdzewski 1993: 112. Shih & Chen 1995: 52­ 53, figs 28–29. Zeidler 1998: 37, 41. Barkhatov et al. 1999: 808 (Table). Vinogradov 1999: 1180, fig. 4.89.

Type material

Four syntypes of V. stebbingi are in the ZMB (unregistered). Behning and Woltereck (1912) do not specify a holotype. They record six specimens from the mid­Atlantic, from Valdivia Stns 48b (0º9’S, 8º30’W), 49 (0º20’N, 6º45’W), 54 (1º51’N, 0º31’E) and 55 (2º37’N, 3º38’E). The figured female is from Stn. 54.

Material examined (> 300 specimens)

Types. Four syntypes of V. stebbingi from Valdivia Stns 48b, 54 and 55: all in spirit, the one from Stn. 54 with head missing.

Other material examined. Tasman Sea: 7 lots (SAMA), 11 specimens. North Atlantic: 5 lots (BMNH), 13 lots (CMN), 3 lots (USNM), 7 lots (ZMB), 3 lots (ZMUC), 48 specimens. South Atlantic: 1 lot (BMNH), 28 lots (SAM), numerous specimens. North Pacific: 1 lot (LACM), 3 lots (USNM), 10 specimens. South Pacific: 2 lots (BMNH), 23 specimens. South Indian: 1 lot (BMNH), 63 lots (SAM), 10 lots (SAMA), 174 specimens. Central Indo­Pacific: 1 lot (USNM), 1 specimen. Gulf of Eilat: 1 lot (ZMB), 1 specimen.

Diagnosis

Body length up to 5–6 mm. Antennae 1 length slightly shorter than head and first three pereonites; flagellum with more or less parallel margins, obliquely truncate ventrally for distal third (broader and longer in males). Gnathopod 2; carpal process about halflength propodus (or marginally more). Pereopods 3 & 4; dactylus length about half propodus. Pereopods 5 & 6; dactylus length about 0.3x propodus. Pereopod 7; basis rectangular, width about half length, slightly longer than ischium to carpus combined, with small, sharp anterodistal lobe and narrow, rounded posterodistal lobe overlapping ischium and about half of merus. Lateral corners of last urosomite not produced. Uropod 3; peduncle distinctly longer than rami; sexual dimorphism of endopod not evident. Telson triangular, pointed, length about half peduncle of U3.

Remarks

This is a very small species of Vibilia. Its similarity to V. antarctica and V. propinqua has already been discussed under those species. It is also similar to V. viatrix, but in that species the carpal process of gnathopod is as long as the propodus, pereopods 3 and 4 have relatively thicker articles and a longer dactylus, and the basis of pereopod 7 is without an anterodistal lobe.

Apart from its small size and short carpal process of gnathopod 2, the most readily distinguishing character for V. stebbingi seems to be the shape of the basis of pereopod 7. In no other congener, except perhaps for V. australis, is the anterodistal corner as well developed, overlapping the ischium.

Vibilia stebbingi has been recorded as an associate of the salps Salpa fusiformis, S. maxima and Cyclosalpa polae (Madin & Harbison 1977).

Distribution

This is a relatively uncommon, but widely distributed species in tropical and subtropical waters including the Mediterranean Sea. However, it was relatively common and abundant in collections from off the east coast of South Africa (SAM).